The current applicants propose that the emotional reactions of children who stutter and their attempts to regulate these reactions contribute to the exacerbation and maintenance of their stuttering. The applicants' model of childhood stuttering suggests that subtle and not-so-subtle linguistic, motoric and communicative difficulties (e.g., Anderson & Conture, 2004; Pellowski & Conture, in press) may initiate stuttering in ayoung child. Subsequently, the child reacts to instances of stuttering by becoming more aroused and reactive, and these reactions may or may not be modulated by the child's regulatory or coping skills. Our model predicts that levels of emotional reactivity and regulation/coping of children who stutter will differ from those of their normally fluent peers. We also predict that changes in emotional reactivity and regulation will beassociated with changes in stuttering. We will examine the following hypotheses for 3- to 5-year-old children who do and do not stutter: (1) Are there naturally-occurring differences between children who do and do not stutter with regard to emotional reactivity and regulation as rated by parents and trained examiners (Proposed Study 1)? (2) Are there differences between children who do and do not stutter with regardto emotional reactivity and regulation during structured laboratory situations (Proposed Study 2)? (3) Does emotional reactivity differ between children who do and do not stutter when presented with arousing environmental stimulation and is reactivity associated with stuttering and other disfluencies (Proposed Study 3)? (4) Do experimental variations in emotion regulation influence stuttering for children who stutter (Proposed Study 4)? These studies are an initial attempt to relate emotional development and behavior to childhood stuttering when children areconfronted with change or challenge. These interdisciplinary investigations - involving collaboration between developmental psychology and speech-language pathology- should help determine whether some children who stutter are less able to regulate distress or modulate their reactivity and clarify the link between emotional reactivity, regulation, and childhood stuttering. Results will ground the study of childhood stuttering within the broader context of childhood emotional development, and focus future research on issues that inform diagnostic and treatment protocols for childhood stuttering.